Other Chemistry Commons^™

I. Non-Degradable Polysiloxane Networks For Controlled Release Applications, And Ii. Additive Free, Degradable Silyl-Ether Furyl-Maleimide Networks, Caleb M. Bunton

Chemistry Theses and Dissertations

I. Two different series of non–degradable polysiloxane networks were prepared for the encapsulation and controlled release of a small molecule agent. For the first series, hydrosilylation was utilized to prepare networks of varying crosslink densities, as determined from swelling studies, from vinyl terminated and silylhydride functional poly(dimethyl)siloxanes. For the second series, the thiol-ene reaction was utilized to prepare networks of varying crosslink densities, as determined from swelling studies, from vinyl terminated and mercaptopropyl functional poly(dimethyl)siloxanes. Nile red dye was used as an encapsulated agent and dye release from each series of networks was measured using UV–vis spectroscopy to determine controllability …

Chemistry In Art: The Science Of Dye, Madeleine Gray Burland

Honors Projects

Fabric arts, and the practice of dyeing fabric using various resist techniques, is a tradition that goes back centuries, and is unique among art mediums in its relation to science, as the innovations in dye production have directly affected the art form. The development of synthetic dyes in the 1800’s greatly affected the way fabric is dyed, and subsequently the way clothes were made and consumed. As opposed to dyes made of natural materials, synthetic dyes cam in more colors, were brighter, easier to make in large quantities, and lasted longer since they didn’t fade with repeated washings. The practice …

Mechanistic Study Of Cooperative Ligand-Centered Reactivity In Triaminoborane-Bridged Diphosphine Complexes, Clara Kirkvold

Honors Thesis

Reactive ligand platforms containing trisubstituted boranes have been effective in promoting new types of small molecule reactivity and catalysis with transition metals. Our project is aimed at developing triaminoborane-bridged diphosphines that participate in cooperative ligand-centered reactivity while bound to transitions metals. Here we present a density functional theory (DFT) mechanistic study on a series of ligand centered reactions at a boron center on a metal complex, ^PhTBDPhosMCl₂ (M = Ni or Pd and TBDPhos = 1,8,10,9-triazaboradecalin). Our work focuses specifically on the nickel complexes. ^PhTBDPhosNiCl₂ can react with several molecules to produce trans H-X addition (X=OH …

Isolation, Identification, And Investigation Of A Novel Bioactive Furanocoumarin From Leaves Of Amyris Elemifera, Amy K. Bracken

Honors Theses

Plants produce biologically active compounds that humans have utilized for many agricultural applications. Amyris elemifera was investigated due to the known bioactivity of its family, Rutaceae, and its use in medicines in tribes of the Bahamas. Biotage® and TLC guided fractionation of the EtOAc, hexane, and MeOH extracts of the leaves of Amyris elemifera yielded bioactive compounds. Most significantly, a novel furanocoumarin, 8-(3-methylbut-2-enyloxy)-marmesin acetate (1), and its analog 8-(3-methylbut-2-enyloxy)-marmesin (2), were isolated. The structures were identified via NMR and X-ray crystallography techniques; the X-ray crystal structure for 1 was reported for the first time, and the …

Effect Of Charged Lipids On The Ionization Behavior Of Glutamic Acid Containing Transmembrane Helices, Brooke Nunn

Chemistry & Biochemistry Undergraduate Honors Theses

Transmembrane proteins make up critical components of living cells. Protein function can be greatly impacted by the charged state of its respective components, the side chains of amino acid residues. Thus far, in the lipid membrane, little is known about the properties of residues such as glutamic acid. To explore these properties, I have included glutamic acid in a suitable model peptide-lipid system for fundamental biophysical experiments. Within the system, I have placed a glutamic acid residue instead of leucine in the L14 position of the helical hydrophobic peptide GWALP23 (acetyl-GGALWLALALALAL¹⁴ALALWLAGA-amide). Substitutions of glutamine and aspartic acid serve …

Resolution Of Portable Raman Spectrometers And Its Effect On The Analysis Of Biological Specimens, Jalissa Thomas

Chemistry

Body fluid traces are a common and a major form of evidence that can be found at a crime scene, as it is a good source of DNA. As such, it is vital that body fluid evidence is properly detected and identified. Issues with the current methods of identifying body fluids and the large backlog of evidence in most forensic labs call for more accurate on-scene (in situ) body fluid identification. Past research has demonstrated that Raman spectroscopy is an advantageous tool for accurately and quickly identifying body fluids, namely in the laboratory. Portable Raman instruments have been …

The Ability Of Vitreous Metabolite Concentration To Determine Time Of Death, Victoria Wiggins

Themis: Research Journal of Justice Studies and Forensic Science

This paper analyzes the ability of vitreous fluid to determine time of death. The high variability in current methods used to establish post-mortem interval (PMI), or the amount of time between death and post-mortem examination make it difficult to obtain an accurate estimation. The concentration of metabolites found within vitreous fluid, such as potassium (K+), hypoxanthine (Hx), and magnesium (Mg), are the most researched alternatives to traditional methods in PMI determination because of the relative isolation of vitreous within the body and its ability to withstand degradation. There is no clear consensus on which metabolite provides the most accurate data …

295— Biomimicry: Investigating The Active Site Model Of Lactate Racemase, Stephanie Podguski, Maisy Ross

GREAT Day Posters

Because of humans’ heavy impact on nature with industrialization and resource extraction, biomimetics, also known as biomimicry, is a study that has emerged. Biomimetics utilizes observations from nature to comprehend the principles of underlying mechanisms and apply concepts that may benefit science, medicine, engineering and the like. An area of biochemistry we are applying this to is the lactate racemase enzyme.This metalloenzyme is found in many prokaryotic organisms and catalyzes the interconversion between the two optical isomers of lactic acid. The structure of this enzyme consists of a square-planar nickel (II) ion coordinated by a histidine residue and a pincer …

Biological Evaluation Of Fda-Approved Drugs As Mirna-31 Inhibitors Using Real Time Qrt-Pcr And A Luciferase Assay, Nicholas Sienkiewicz

Honors Theses

MicroRNAs (miRNAs) are a group of post-transcriptional, negative regulators of gene expression, consisting of ~19-24 nucleotides. Since their discovery in 1993, miRNAs have been found to be involved in a diverse amount of cellular and disease pathways, including certain types of cancer. Overexpression of certain oncogenic miRNAs, including miRNA-31, have been shown to play a role in cancer cell development. Recent findings have suggested that miRNAs play a significant role in every stage of colorectal cancer (CRC) initiation, progression, and development, as well as induce resistance to chemotherapy drugs like 5-FU. In particular, research has shown that increased levels of …

Quantification Of Vitamin B12 In Two Cricket Species, Haley Smeltz

Student Scholar Showcase

Entomophagy, or the eating of insects, has been practiced in the eastern world for centuries, however it is currently overlooked in the western nations. Studies have shown that insects, such as crickets, contain high levels of protein and minerals, however vitamin content is rarely studied. This study aims to quantify the vitamin B₁₂ content in two cricket species, the common house cricket (Acheta domesticus) and the banded cricket (Gryllodes sigillatus). The vitamin B₁₂ content of both cricket species will be quantified using reverse-phase high performance liquid chromatography (RP-HPLC). Prior to RP-HPLC analysis, all the …

Chemistry 104 Laboratory Manual, Boris Kalmatsky

Open Educational Resources

No abstract provided.

Using Surface-Enhanced Raman Scattering Of Gold Nanostars For Encoding Molecular Information, Samantha E. Curry

Honors Thesis

Increases in the selling of illicit goods warrant a subsequent need for even more sophisticated methods to prevent counterfeit products from being sold. Surface-enhanced Raman spectroscopy (SERS) has the potential to be a powerful tool to thwart counterfeiters because the unique security tags fabricated with this method are difficult to reproduce without knowing the “secret” recipes used in their preparation. In this work, gold nanostars are used as SERS active substrates since their branched structure allows for strong coupling between the light and plasmonic nanoparticles. As a result, Raman signals of trace amount of chemicals can be easily detected. The …

Quantum Chemical Lipophilicities Of Antimalarial Drugs In Relation To Terminal Half-Life, Joseph D. Alia, Sheila Karl, Tyler D. Kelly

Chemistry Publications

According to the WHO, artemisinin-based combination therapies (ACTs) have been integral to the recent reduction in deaths due to Plasmodium falciparum malaria. ACT-resistant strains are an emerging problem and have evolved altered developmental stages, reducing exposure of the most susceptible stages to artemisinin drugs in popular ACTs. Lipophilicity, log K_ow, is a guide in understanding and predicting pharmacokinetic properties such as terminal half-life which alters drug exposure. Consistent log K_ow values are not necessarily available for artemisinin derivatives designed to extend terminal half-life, increase bioavailability, and reduce neurotoxicity. For other drugs used in ACTs, an assortment of …

Understanding The Oxidative Chemistry Of Particulate Methane Monooxygenase Models., Thomas Jones

Research Horizons Day Posters

No abstract provided.

Characterization Of Dimerization Domains On The Mannose-6-Phosphate/Insulin-Like Growth Factor 2 Receptor, Tyler Degener

UNO Student Research and Creative Activity Fair

The mannose-6-phosphate/insulin-like growth factor 2 (M6P/IGF2) receptor is a transmembrane protein with the ability to sequester growth factors from the extracellular matrix. This behavior links the receptor to tumor suppression. On a structural level, the extracellular portion of the protein is segmented into 15 homologous repeats, which can be divided further into 5 triplet domains, labelled 1-3, 4-6, 7-9, 10-12, and 13-15. Each triplet receptor displays its own unique ligand binding affinity, including the ability to form dimers with triplets on a second M6P/IGF2 receptor. In fact, previous studies indicate that this protein functions optimally when dimerized. Thus, the purpose …

Hydrogen Peroxide Triggers An Increase In Cell Surface Expression Of System XC− In Cultured Human Glioma Cells, Leah A. Chase, Mary Verheulen Kleyn, Natasha Schiller, Abby Goltz King, Guillermo Flores, Sasha Balcazar Engelsman, Christina Bowles, Sara Lang Smith, Anne E. Robinson, Jeffrey Rothstein

Faculty Publications

System x_c⁻ exchanges extracellular cystine for intracellular glutamate across the plasma membrane of many cell types. One of the physiological roles of System x_c⁻ is to provide cystine for synthesis of the antioxidant glutathione. Here we report that hydrogen peroxide (H₂O₂) triggers the translocation of System x_c⁻ to the plasma membrane within 10 min of the initial exposure. Specifically, we observed a three-fold increase in ³⁵S-L-cystine uptake following a 10 min exposure to 0.3 mM H₂O₂. This effect was dose-dependent with an EC₅₀ for …

Quantitative Trait Loci (Qtl) Underlying Phenotypic Variation In Bioethanol-Related Processes In Neurospora Crassa, Joshua C. Waters, Deval Jhaveri, Justin C. Biffinger, Kwangwon Lee

Chemistry Faculty Publications

Bioethanol production from lignocellulosic biomass has received increasing attention over the past decade. Many attempts have been made to reduce the cost of bioethanol produc- tion by combining the separate steps of the process into a single-step process known as consolidated bioprocessing. This requires identification of organisms that can efficiently decompose lignocellulose to simple sugars and ferment the pentose and hexose sugars lib- erated to ethanol. There have been many attempts in engineering laboratory strains by add- ing new genes or modifying genes to expand the capacity of an industrial microorganism. There has been less attention in improving bioethanol-related processes …

The Use Of A Modified Hess’ Cognitive Rigor Matrix To Assess Students’ Depth Of Knowledge In Key Concepts Of Gas Stoichiometry And Chemical Equilibrium, Maria Greene

Dissertations, Theses, and Capstone Projects

The research presented as part of this dissertation is a combination of two separate studies conducted to assess and evaluate undergraduate general chemistry students’ understanding and depth of knowledge (DOK) of concepts in gas stoichiometry and chemical equilibrium. The two separate studies were conducted using a modified Hess Cognitive Rigor Matrix (CRM) to analyze students’ responses to multiple-choice questions (MCQ) and their written rationales to their answer choices. The Hess Cognitive Rigor Matrix, which is an incorporation and coordination of both Bloom’s and Webb’s DOK taxonomies, allowed the facilitation of the opportunity to code students’ written responses across the four …

Resolving The Puzzle Of Single-Atom Silver Dispersion On Nanosized Γ-Al2o3 Surface For High Catalytic Performance, Fei Wang, Jinzhu Ma, Shaohui Xin, Qiang Wang, Jun Xu, Changbin Zhang, Hong He, Xiao Cheng Zeng

Department of Chemistry: Faculty Publications

Ag/γ-Al2O3 is widely used for catalyzing various reactions, and its performance depends on the valence state, morphology and dispersion of Ag species. However, detailed anchoring mechanism of Ag species on γ-Al2O3 remains largely unknown. Herein, we reveal that the terminal hydroxyls on γ-Al2O3 are responsible for anchoring Ag species. The abundant terminal hydroxyls existed on nanosized γ-Al2O3 can lead to single-atom silver dispersion, thereby resulting in markedly enhanced performance than the Ag cluster on microsized γ-Al2O3. Density-functional-theory calculations confirm that Ag atom is mainly anchored by the terminal hydroxyls on (100) surface, forming a staple-like local structure with each Ag …

Methods Of Making And Using Lignin Derivatives, Mark Alan Helle, Chin Li Cheung

Department of Chemistry: Faculty Publications

Materials and methods for preparing reactive lignin and for preparing a bio-based adhesive are described herein.

This disclosure generally relates to methods of making and using reactive lignin. This disclosure also generally relates to methods of making and using bio-based adhesives. Lignin is the second most abundant natural polymer behind cellulose, yet lignin has very little commercial value despite years of research. Lignin is one of the major components of the cell wall in wood and other plant based materials such as hemp or crop wastes. It is produced in enormous quantities each year, primarily as a by-product in the …